1. Field of the Invention
The present invention relates to a liquid crystal display device. More particularly, the present invention relates to a liquid crystal display device characterized by the structure of a wire inspection terminal of a thin-film transistor substrate.
2. Description of the Related Art
A liquid crystal display device is composed of a liquid crystal display panel, a drive circuit, and a back light, etc. as required. The liquid crystal display panel is formed by laminating first and second substrates, and a liquid crystal layer is encapsulated in an opposing gap between inner surfaces, i.e., main surfaces thereof. A plurality of scanning wires and a plurality of data wires are formed on the main surface of the first substrate, the data wires intersecting with the scanning wires through an insulating layer. A pixel is formed at an intersection of a scanning wire and a data wire, and a pixel area (effective display area) is formed by arranging pixels in matrix form. Aluminum is suitably used for these wires.
FIG. 4 is a schematic plan view showing a configuration of a liquid crystal display panel. In FIG. 4, SUB1 shows the first substrate and SUB2 the second substrate. A plurality of scanning wires GL and a plurality of data wires DL are formed on the first substrate SUB1, the data wires DL being insulated from and intersecting with the scanning wires GL. A wire inspection terminal CKP (inspection pad), which is circled and indicated by an arrow A, is formed at the end of each scanning wire GL. The wire inspection terminal CKP includes a contact portion with an inspection probe. A scanning wire drive circuit chip GD is connected to the other end of each scanning wire GL.
A plurality of data wires DL are formed so as to intersect with the above-mentioned scanning wires GL through an insulating layer. A data wire drive circuit chip DD is connected to the end of each data wire DL. A wire inspection terminal (not shown) is formed also at the end on the opposite side of the end to which the data wire drive circuit chip DD for data wires DL is connected.
On the other hand, a color filter for a plurality of colors (normally red, green, and blue) is formed on the main surface of the second substrate SUB2. The second substrate SUB2 is laminated on the first substrate SUB1, the substrates being bonded with sealing agent SL. In this case, liquid crystal is injected from a notch made at a part of the sealing agent SL and then the notch is sealed with sealing agent STP.
With an active-matrix type liquid crystal display panel, since a thin-film transistor is formed near each intersection of the scanning wires GL and data wires DL on the first substrate SUB1, this substrate is also referred to as thin-film transistor substrate. Furthermore, since the color filter is formed on the second substrate SUB2, this substrate is also referred to as color filter substrate.
FIG. 5 is a diagram illustrating a condition wherein inspection probes are contacted with the wire inspection terminals to inspect disconnection of scanning wires. A plurality of inspection probes PB arranged in a row are lowered and then contacted with the contacts for inspection probe of the wire inspection terminals CKP included in the first substrate SUB1, as shown by an arrow, to inspect the presence of disconnection by use of a measuring apparatus (not shown). A technique related to such disconnection inspection is disclosed in JP-A-2001-324721.